本文選題：車載自組織網(wǎng)絡 + 介質訪問控制�。� 參考：《南京郵電大學》2016年碩士論文

【摘要】：車載自組織網(wǎng)絡(Vehicular Ad-hoc Network,VANET)作為智慧交通系統(tǒng)的重要組成部分,能夠為用戶帶來安全舒適的行車體驗。而VANET的網(wǎng)絡性能取決于介質訪問控制(Medium Access Control,MAC)協(xié)議。由于VANET網(wǎng)絡具有車輛移動速度快、網(wǎng)絡拓撲快速變化等特點,使得原有的IEEE 802.11p協(xié)議中基于載波偵聽多路訪問/沖突避免的MAC協(xié)議無法滿足安全應用的要求。因此,如何針對VANET的特點來改進現(xiàn)有的MAC協(xié)議,使其滿足安全應用對廣播消息的平均到達時延和接收率的要求是十分必要的。本文針對以上問題進行深入探究,主要工作如下:首先,建立車載自組織網(wǎng)絡中具有優(yōu)先級的安全消息傳輸性能分析模型,通過該模型分析出狀態(tài)消息存在的情況下緊急消息的平均傳輸時延;仿真結果驗證了該模型的正確性,該模型對選取合適的網(wǎng)絡參數(shù)來減小緊急消息的傳輸時延及進一步研究VANET的其他性能具有一定的參考價值。其次,針對IEEE 802.11p的MAC層協(xié)議以及現(xiàn)有的改進協(xié)議在車輛密度較高的情況下性能較差的問題,研究了一種基于多數(shù)據(jù)速率的MAC協(xié)議(Multiple-Data-Rate MAC,MDR-MAC)。該協(xié)議通過引入多數(shù)據(jù)速率的方式減小了消息的傳輸時間,降低了網(wǎng)絡擁塞;通過集中式時隙分配的方式減小了消息之間的碰撞,從而保證了信標消息的有效廣播;仿真結果表明該協(xié)議在信標消息的接收率和平均到達時延方面的性能均有所提升。最后,為進一步優(yōu)化緊急消息傳輸?shù)挠行院涂煽啃?本文研究了緊急消息的時隙預約機制和協(xié)作傳輸機制。時隙預約機制通過減小緊急消息接入信道的時延,提高了緊急消息的傳輸有效性;協(xié)作傳輸機制通過識別接收緊急消息失敗的節(jié)點、選擇輔助節(jié)點、重傳消息這一過程提升了緊急消息的接收率,從而提高了緊急消息的傳輸可靠性。仿真結果表明該機制能夠保證緊急消息的實時可靠傳輸。
[Abstract]:As an important part of intelligent transportation system, vehicle Ad-hoc Network (VANET) can bring users a safe and comfortable driving experience. The network performance of VANET depends on medium Access Control (MAC) protocol. Because of the fast moving speed of vehicle and the rapid change of network topology, the MAC protocol based on carrier listening multiple access / collision avoidance in the original IEEE 802.11p protocol can not meet the requirements of security applications. Therefore, it is necessary to improve the existing MAC protocol according to the characteristics of VANET to meet the requirements of the security applications for the average delay of arrival and reception rate of broadcast messages. The main work of this paper is as follows: firstly, the security message transmission performance analysis model with priority in vehicular ad hoc network is established. Through this model, the average transmission delay of emergency message in the presence of state message is analyzed, and the simulation results verify the correctness of the model. This model has some reference value for selecting appropriate network parameters to reduce the transmission time of emergency messages and to further study the other performance of VANET. Secondly, aiming at the problem that the MAC layer protocol of IEEE 802.11p and the existing improved protocol have poor performance in the case of high vehicle density, a MAC protocol based on multi-data rate (MAC), Multiple-Data-Rate Marc, is studied. The protocol reduces the transmission time and network congestion by introducing multi-data rate, reduces the collision between messages by centralized slot allocation, and ensures the effective broadcast of beacon messages. The simulation results show that the performance of the proposed protocol is improved in terms of the reception rate and the average arrival delay of the beacon message. Finally, in order to optimize the efficiency and reliability of emergency message transmission, the slot reservation mechanism and cooperative transmission mechanism of emergency message are studied in this paper. Slot reservation mechanism improves the transmission efficiency of emergency message by reducing the delay of emergency message access channel, and cooperative transmission mechanism selects auxiliary nodes by identifying the node that has failed to receive emergency message. The process of retransmitting messages improves the receiving rate of emergency messages and improves the transmission reliability of emergency messages. Simulation results show that this mechanism can guarantee the real-time and reliable transmission of emergency messages.
【學位授予單位】：南京郵電大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：TN929.5;U495

【相似文獻】

相關碩士學位論文 前1條

1 于明鷺;車載自組織網(wǎng)絡下的介質訪問控制協(xié)議研究[D];南京郵電大學;2016年

，

本文編號：1866201